Japan does not allow dual nationality, so she was obliged to give up her Japanese citizenship and may reapply to get it back only after ten years.

[8] Kavaguti said, "We had a good working relationship but it was very difficult for Alexander to acquire Japanese citizenship, thus we couldn't represent Japan in the Olympics so after a while we decided to break up.

"[15] In 2003, Kawaguchi followed her coach as Moskvina moved back to Saint Petersburg, Russia where she enrolled at a university in addition to skating.

Kavaguti dislocated her shoulder after a fall on a quad throw in 2006 and occasionally suffered recurring problems for several years after.

At the Cup of Nice they place 1st in both the short and long program and won the gold for the second year in a row.

They won by 10.43 points over Maria Mukhortova / Maxim Trankov in spite of a three-point deduction for stopping the program due to injury.

During the long program they landed the throw quad Salchow but a fall on a triple jump and planned double Axel that was turned into a single was only enough for a bronze medal.

They landed a throw quad Salchow and several elements received a level four but they dropped to fourth place only 1.45 points out of third.

At the 2009 European Championship the pair who was in 3rd place after the short improved on the previous year's placement with a silver medal.

At the Cup of Russia they placed second in the short program and free skate, winning the silver medal behind Pang/Tong.

They skated at the 2010 European Championships in Tallinn, Estonia and were second after the short with less than one point separating the top three pairs.

Much like the World Championships in 2009, they were second after the short program and after a fall they dropped to third in the free skate; less than a point out of 2nd place.

Kavaguti/Smirnov competed at their only Grand Prix competition at the 2010 Cup of Russia where they were first in the short program and won the free skate by over 17 points.

The 2011 World Championships were originally scheduled to be held in Tokyo in March but due to the devastating earthquake and tsunami, the competition was moved to Moscow in late April.

In the short program, Kavaguti's fall on an under-rotated triple toe loop combined with several elements receiving lower levels left the pair in 5th place with a score of 55.02.

They placed first in the free skate and won the gold medal with a total score of 177.51 over reigning World Champions Aliona Savchenko / Robin Szolkowy.

At the Grand Prix Final, they placed fourth in the short program with a score of 61.37[25] and third in the free skate with 126.40, winning the bronze medal with a total of 187.77.

On 20 December 2011, Moskvina said they had requested to be excused from the 2012 Russian Championships to allow Smirnov to heal from a knee injury which arose before the Grand Prix Final.

[30][31][32] Since he was unable to recover in time for the pair to compete at the European Championships in Sheffield, Great Britain from 23 to 29 January they were replaced by Ksenia Stolbova / Fedor Klimov.

[31] At the 2012 World Championships in Nice France, Kavaguti/Smirnov were skating well during their short program until a bad fall at the end of a lift put them in 11th place with a score of 59.59.

[33] After August test skates, the pair decided to replace their planned short program to Cats with one set to a Strauss waltz.

At the 2012 Grand Prix Final, Kavaguti/Smirnov scored 58.02 after the short program due in part to a fall by Kavaguti on a throw and errors by both on the triple toe loops.

Although their only mistake was a doubled triple toe loop by Kavaguti, low levels on some of the elements placed them in 5th in the free skate with a score of 120.70.

[citation needed] For the 2013–14 Grand Prix series, Kavaguti/Smirnov were assigned to the NHK Trophy and Skate Canada, both events that they had previously won.

In October 2013, Smirnov suffered a ruptured patellar tendon in a fall while competing at the Panin Memorial in Saint Petersburg.

[35] Kavaguti/Smirnov returned to competition at a Challenger Series event, the 2014 Nebelhorn Trophy, winning the gold medal with a total of 195.89 points and a quadruple Salchow throw in their free skate.

At their next GP event, the 2015 Rostelecom Cup, they won the silver medal behind teammates Ksenia Stolbova / Fedor Klimov and qualified for the 2015–16 Grand Prix Final.

In December, they won the bronze medal at the GP Final in Barcelona after placing second in the short and third in the free skate.

On 20 January 2016, Kavaguti sustained a ruptured tendon in practice,[39] resulting in the pair's withdrawal from the 2016 European Championships.

On 30 September to 2 October 2016, Kavaguti/Smirnov returned to international competition in an ISU Challenger Series at the 2016 Ondrej Nepela Trophy where they won the silver medal behind teammates Evgenia Tarasova and Vladimir Morozov.